EP2473382A1

EP2473382A1 - Occupant protection device having a safety valve

Info

Publication number: EP2473382A1
Application number: EP10766229A
Authority: EP
Inventors: Jochen Benz; Lars Mast; Jochen Lang; Christoph Pechhold; Robert Fleischmann
Original assignee: Takata AG
Current assignee: Takata AG
Priority date: 2009-09-04
Filing date: 2010-08-30
Publication date: 2012-07-11
Anticipated expiration: 2030-08-30
Also published as: EP2473382B1; CN102481890A; WO2011026474A1; DE102009040690A1; JP2013503770A; CN102481890B; US20120146317A1; JP5669845B2; RU2012105236A; US8585091B2

Abstract

The invention relates, among other things, to an occupant protection device having a pyrotechnical gas generator (40). According to the invention, a safety valve (200) that operates according to temperature and leads to the outside is connected to the gas generator.

Description

description

Occupant protection device with safety valve

The invention relates to an occupant protection device with a pyrotechnic gas generator. For the purposes of this application, occupant protection devices are formed, for example, by components of restraint systems for protecting vehicle occupants, for example by components of belt retractors, components of belt tensioners or components of airbag devices, or by restraint systems as such, for example by belt retractors, belt tensioners or airbag devices as such.

The invention has for its object to provide an occupant protection device with a pyrotechnic gas generator, which provides a particularly high level of security.

This object is achieved by an occupant protection device with the features of claim 1. Advantageous embodiments of the occupant protection device according to the invention are specified in subclaims.

Thereafter, an occupant protection device according to the invention is provided with a pyrotechnic gas generator, in which with the gas generator is an outwardly leading temperature-dependent working safety valve in communication.

A significant advantage of the occupant protection device according to the invention is the fact that it also provides a very high degree of safety for the vehicle occupants located in the vehicle in the event of a vehicle fire. Even in case of fire, so if a very high temperature in the driving occurs and the gas generator due to the high temperature automatically, ie without deliberate external ignition triggers, there may be no injury to the vehicle occupants; because the leading outward temperature-dependent safety valve can ensure that the safety valve opens in time and the gas generated by the gas generator can escape through the safety valve to the outside. By the temperature-dependent working safety valve can thus ensure that gas from the gas generator is discharged to the outside, when a predetermined limit temperature is exceeded.

Another important advantage of the occupant protection device according to the invention is that it must be designed only for normal pressures within the nominal operating temperature range, as an overpressure due to a fire-related pressure gain and concomitant risk of bursting the entire occupant protection device because of the safety valve does not have to be considered.

In order to ensure a particularly high level of functional safety in the event of fire, it is considered advantageous if the safety valve comprises a closure element which seals the safety valve in a gastight manner, ie even when gas is applied by the gas generator, as long as the material temperature of the closure element falls below a material limit temperature. The closure capability of the material of the closure element is preferably reduced when the material limit temperature is exceeded, so that the safety valve is released at the latest when gas is applied by the gas generator. The material limit temperature is preferably lower than the autoignition temperature of the gas generator and preferably greater than the maximum temperature. temperature of the nominal operating temperature range of the gas generator. The maximum nominal operating temperature of a gas generator is usually around 100 ° C.

A temperature-dependent working safety valve may be formed for example by an opening or bore in a pipe or an opening or bore in a gas-carrying carrier, which is closed by a plug. The material and the shape of such a plug are preferably designed such that the plug loses its strength and / or its shape above a predetermined functional temperature, for example above 105 ° C. Such a plug may for example be formed by a plastic plug, which is welded in the opening or clipped or glued or riveted to this. Instead of a plastic plug also plugs made of other materials (eg metals with a melting point between 100 ° C and 130 ° C) can be used; also, for example, plug can be used with a fusible filling. For example, an alloy, for example a solder alloy, can be used as the filling. It is also possible to use adhesive films that shrink, melt or burn, for temperature-dependent closing of an opening or a hole.

Also, to close an opening or bore, a combustible material may be used which burns when the flame or heat is open thereby releasing the opening or bore.

The safety valve can for example be attached directly to a gas-carrying pipe. Alternatively, it is also possible to mount the safety valve in the area of carriers. animals that are directly or indirectly connected to the gas generator. For example, threaded plugs can be used with holes that are closed by solder: melts the solder, the hole of the threaded plug is released and the safety valve is opened.

As already mentioned, a variety of different configurations for the temperature-dependent working safety valve is conceivable. However, it is considered to be particularly advantageous if the safety valve comprises a hole in a wall of a feed element and a closure element which is inserted from the outside into the hole, and the closure element has at least two snap elements which snuggle with the wall and on the inside of the Abut the wall.

Particularly preferably, such a closure element has a recess into which a locking element can be inserted from the outside. Such an inserted locking element preferably results in that at least two snap elements of the closure element are pressed radially outward, so that the snap elements are pressed laterally against the hole wall of the hole. By such a pressing of the snap elements radially to the hole wall can be prevented in a particularly simple manner that the closure element is pushed out of the hole by overpressure and the safety valve is opened, although the intended opening of the safety valve limit or opening temperature is not reached. In other words, it is ensured by the closure element in a particularly simple manner that the safety valve works only temperature-dependent and not additionally dependent on pressure. The closure element as a whole or alternatively only the Locking element are preferably made of a material that loses its ability to lock when a limit temperature is exceeded, for example by melting, deformation or burning. The closure element as a whole or, alternatively, only the locking element may for example consist of plastic, metal or a metal alloy with a melting temperature between 110 ° C and 130 ° C.

In order to simplify a pivoting of the snap elements radially outward, it is considered advantageous if the recess in the closure element is formed by a through hole which is closed by the locking element. In this embodiment, the snap elements can be completely separated from each other in the region of the hole and thus be pivoted particularly easily, so that a particularly firm connection of the closure element to the feed element can be ensured with the aid of the locking element. In this embodiment, it is otherwise sufficient if only the locking element consists of a material which loses its ability to lock when the limit or opening temperature is exceeded; the remaining parts of the closure element may consist of a more temperature-resistant material.

According to another preferred embodiment, it is provided that the safety valve comprises a closure element which is formed by a pin comprising a pin head. The pin is inserted from the inside into a hole in a wall of a feed element, for example a feed tube, such that the pin head bears against the inside of the wall. Subsequently, the pin end projecting outwardly through the hole is formed to form a closure seal. Section, which is larger in cross section than the cross section of the hole, plastically deformed. The temperature-dependent safety valve is thus formed in this case by a plastically deformed pin with pin head, which is inserted through a hole in a wall of a feed element. The pin is preferably made of a material that loses its ability to close when a limit temperature is exceeded, for example by melting, deformation or burning. The limit temperature is preferably in a temperature range between 110 ° C and 130 ° C.

Alternatively or additionally, the safety valve may also comprise a closure element in the form of a blind rivet, which is inserted from the outside into a hole in a wall of a feed element and riveted to the wall. Such riveting is preferably carried out with a corresponding riveting tool. The blind rivet is preferably made of a material which, when a limit temperature is exceeded, for example, between 110 ° C and 130 ° C, loses its sealing ability, for example by melting, deformation or burning.

According to another preferred embodiment, it is provided that the safety valve comprises a closure element in the form of a film, which is placed on a hole in a wall of a feed element from the outside or from the inside and closes the hole. In this embodiment, a particularly simple assembly is possible, since only a film in the region of a hole of the feed element must be attached. The film is preferably made of a material which, when a limit temperature is exceeded, which is for example between 110 ° C and 130 ° C, its closure capability loses, for example, by melting, deformation or burning.

The occupant protection device is preferably a belt retractor with a pretensioner drive which comprises the gas generator, a drive device connected to the belt spindle of the belt retractor and a feed element, in particular in the form of a supply pipe, which connects the gas generator and the drive device. Preferably, a plurality of thrust bodies are present in the feed element, which are accelerated after triggering of the gas generator and drive the drive device for winding the seat belt directly or indirectly. The safety valve preferably comprises a hole in the feed element, the hole being particularly preferably arranged in the section between the gas generator and the first push body.

The invention also relates to a method for manufacturing an occupant protection device with a pyrotechnic generator. According to the invention, provision is made in this regard for a hole leading to the outside to be closed in a feed element with a closure element which operates in a temperature-dependent manner.

The invention will be explained in more detail with reference to embodiments; thereby show by way of example

1 shows an embodiment of an occupant protection device according to the invention, which is formed by a belt retractor,

FIG. 2 shows the connection region of a gas generator of the

Belt retractor according to FIG. 1 to a supply tion tube of Gurtaufrollers according to Figure 1 in more detail,

FIG. 3 shows an exemplary embodiment of a temperature-dependent safety valve for the belt retractor according to FIG. 1 during assembly;

FIG. 4 shows the safety valve according to FIG. 3 after completion of the assembly;

5 shows a locking element of the safety valve according to FIGS. 3 and 4 in a plan view,

FIG. 6 shows a further exemplary embodiment of a temperature-dependent safety valve for the belt retractor according to FIG. 1,

FIG. 7 shows a third exemplary embodiment of a temperature-dependent safety valve in the form of a pin with a deformed pin end,

FIG. 8 pin according to FIG. 7 after forming,

9-11 exemplifies the production of a safety valve, which is formed with a blind rivet, wherein FIGS. 9 to 10 show the manufacture of such a blind rivet by way of example and

FIG. 12 shows a further exemplary embodiment of a safety valve for the belt retractor according to FIG Figure 1, wherein the safety valve comprises a film.

For the sake of clarity, the same reference numerals are always used in the figures for identical or similar components.

FIG. 1 shows, in a schematic exploded view, an exemplary embodiment of an occupant protection device which is formed by a belt retractor 10. The belt retractor 10 has, inter alia, a belt spindle 20, a tightening drive 30, and a mass inertia coupling 35 connecting the tightening drive 30 and the belt spindle 20.

The pretensioner drive 30 comprises a pyrotechnic gas generator 40, for example in the form of a micro gas generator, a drive wheel 50, a curved feed pipe 60 connecting the gas generator 40 and the drive wheel 50, and a plurality of masses 70a to 70n. The thrust bodies 70 are, for example, spherical.

The drive wheel 50 is rotatably supported between a retaining cap 51 and a retaining plate 52 and has receiving cups 100 into which the thrust bodies 70 engage to drive the drive wheel. For this purpose, the thrust bodies 70 are tangentially coupled into the drive wheel 50 and run tangentially past it, under engagement in the receiving shells 100, in order subsequently to reach a downstream receptacle 110.

2, the connecting piece between the gas generator 40 and the feed tube 60 is shown in more detail in detail. provides. It can be seen that between the first thrust body 70a and the gas generator 40, an outwardly leading temperature-dependent safety valve 200 is arranged on the supply pipe 60.

Exemplary embodiments of the safety valve 200 are explained in more detail below in connection with FIGS. 3 to 12.

FIG. 3 shows an exemplary embodiment of a safety valve 200, which is formed by a hole 210 in the feed tube 60 and a closure element 220 inserted into the hole 210. The closure element 220 is pushed along the direction of the arrow P through the hole 210, so that two snap elements 230 and 240 of the closure element 220 with the wall 250 of the feed tube 60 can verschnappen. Due to this snapping, the inner edges 260 and 270 of the two snap elements 230 and 240 bear against the inner side 280 of the wall 250.

By snapping the two snap elements 230 and 240, moreover, the outer edge 290 of the closure element 220 is pressed onto the outer side 300 of the wall 250. In addition, there is a concern of the side walls 310 and 320 of the two snap elements 230 and 240 on the hole wall 330 of the hole 210th

In order to prevent the closure element 220 from being pushed out of the hole 210 inadvertently, for example by an overpressure in the feed tube 60, a locking element 350 is provided, which is inserted into a recess in the form of a through hole 360 of the closure element 220. The longitudinal direction of the through-hole 360 and with the longitudinal direction of the locking element 350 preferably extend

perpendicular, at least approximately perpendicular, to the inner edges 260 and 270 of the two snap elements 230 and 240, and / or

- perpendicular, at least approximately perpendicular, to the outer edge 290 of the closure element, and / or

parallel, at least approximately parallel, to the hole wall 330 of the hole 210, and / or

parallel, at least approximately parallel, to the side walls 310 and 320 of the two snap elements 230 and 240.

The task of the locking element 350 is to push the inner surfaces 370 of the two snap elements 230 and 240 radially outwards, ie, outward along the arrow directions R, so that the side walls 310 and 320 are pressed even more firmly against the hole wall 330. In other words, the essential function of the locking element 350 is to make sure that there can be no squeezing out of the closure element 220, as long as a predetermined Ma terialgrenztemperatur for the closure element 220 is not yet reached or not exceeded.

However, if the temperature exceeds the material boundary tempera ture, which is provided by the material of the closure member 220, the sealing element 220 will lose its ability or impermeability (for example, by softening or melting) and at overpressure within the guide tube to 60 from the hole 210th can be pushed out so that the gas of the gas generator 40 can penetrate according to Figure 1 through the hole 210 of the feed tube 60 to the outside. In the embodiment according to FIG. 3, various embodiments are conceivable:

1. The closure element 220 is made entirely of a temperature-sensitive material.

2. All parts of the closure member 220 except for the locking member 350 are made of a temperature sensitive material.

3. Only the locking element 350 is made of a temperature-sensitive material; the remaining components of the closure element 220 consist of a material which is more temperature-resistant.

In the embodiment according to FIG. 3, the locking element 350 can consist, for example, of plastic or metal, in particular a solder material, with a low melting temperature and the remaining components of another material with a higher melting temperature.

FIG. 4 shows, by way of example, the closure element 220 after the locking element 350 has been introduced into the through hole 360 and the assembly of the closure element 220 in the hole 210 has been completed.

FIG. 5 shows by way of example the closure element 220 according to FIGS. 3 and 4 in plan view. One recognizes the closure element 350, which may be configured circular in cross-section, for example.

FIG. 6 shows a further exemplary embodiment of a temperature-dependent safety valve 200 according to FIG Figure 1 shown. One recognizes a closure element 220, which corresponds to the closure element 220 according to FIG. 3 from its construction and its construction. In contrast to the exemplary embodiment according to FIG. 3, only the recess or the through hole 360 and thus the possibility of inserting a locking element 350, as shown in FIG. 3, are missing. The closure element 220 according to FIG. 6 thus locks exclusively by the snap elements 230 and 240, which with their inner edges 260 and 270 on the inside 280 of the wall 250 snapping and with their side walls 310 and 320 on the hole wall 330 of the hole 210 in the feed tube 60 issue. The closure element 220 further comprises an outer edge 290, which rests on the outer side 300 of the wall, in order to ensure the fixation of the closure element 220.

FIG. 7 shows, by way of example, a safety valve 200 for the belt retractor according to FIG. 1, which comprises a pin 400. The pin 400 has a pin head 410 and a pin end 420. For mounting, the pin end 420 is inserted from the inside of the feed tube 60 through the hole 210 until the pin head 410 abuts the inside 280 of the wall 250 of the delivery tube 60. Subsequently, the pin end 420, which is located on the outside 300 of the wall 250, plastically deformed, so that the cross section of the pin end is greater than the cross section of the hole 210 (see Figure 8). The pin 400 is thus connected by plastic deformation fixed to the hole 210 and closes the hole 210 gas-tight. As long as the pin temperature falls below a material limit temperature of the pin, the pin 400 will seal the guide tube 60, even if the gas generator 40 generates a high gas pressure. However, if the material limit temperature of the pin 400 is exceeded, then reduce the sealing ability of the material of the closure element (for example, by softening or melting), so that the pin 400, at the latest when exposed to gas by the gas generator, the hole 210 release and the gas of the gas generator can escape from the feed tube 60 to the outside.

In connection with FIGS. 9 to 11, it is now explained by way of example how a temperature-dependent safety valve with a blind rivet 500 can be formed. Thus, FIG. 9 shows a blind riveting tool 510, with which a blind rivet blank 520 is pushed through a hole 210 in the wall 250 of the feed tube 60.

After the blind rivet blank 520 has been pushed through, the blind riveting tool 510 is activated and the blind rivet blank 520 is deformed. This is shown by way of example in FIG. 10.

As soon as the deformation of the blind rivet 520 has been completed and the blind rivet 500 has been completed, the blind riveting tool 510 is separated from the blind rivet 500. The production of a temperature-dependent safety valve is thus completed. The safety valve is formed by the blind rivet 500 and the hole 210 in the wall 250 of the feed tube 60. The blind rivet 500 will seal the hole 210 gas-tight as long as the temperature of the blind rivet 500 does not exceed the material limit temperature of the blind rivet. If, however, the temperature of the blind rivet reaches or exceeds the material limit temperature, it will completely or partially lose its sealing capability (for example due to softening or melting) and, at the latest when the gas generator 40 overpressures, release the hole 210 and push it out of it. The blind rivet 500 thus forms in cooperation with the hole 210 a temperature-dependent working safety valve that can be used for the belt retractor according to FIG.

FIG. 12 shows by way of example a further variant for a safety valve for the belt retractor according to FIG. 1. The supply pipe 60, in whose wall 250 a hole 210 has been produced, for example by drilling, can be seen. The hole 210 is closed by a foil 600, which has been applied from the outside or from the inside to the hole 210 and closes the hole 210 gas-tight.

As long as the temperature of the film 600 falls below the material limit temperature of the film 600, the film 600 may seal the hole 210 in a gastight manner. If, however, the temperature of the film 600 exceeds the material limit temperature, the film will lose its sealing capability (for example due to softening or melting) and release the hole 210, at the latest when gas is applied by the gas generator 40 according to FIG. The film 600 in conjunction with the hole 210 thus forms a temperature-dependent working safety valve, which can be used in the belt retractor according to FIG.

LIST OF REFERENCE NUMBERS

10 belt retractor

20 belt spindle

30 penalty drive

35 mass inertia clutch

40 gas generator

50 drive wheel

51 retaining cap

52 retaining plate

60 feed tube

70 thrust bodies

100 cradles

110 receptacle

200 safety valve

210 holes

220 closure element

230 snap element

240 snap element

250 wall

260 edge

270 edge

280 inside

290 edge

300 outside

310 side wall

320 side wall

330 hole wall

350 locking element

360 through hole

370 inner surface

400 pen

410 pin head 420 pen end

500 blind rivet

510 blind riveting tool

520 blind rivet blank

600 foil

P arrow direction

R arrow direction

Claims

claims

1. Occupant protection device with a pyrotechnic gas generator (40),

characterized in that

with the gas generator, an outwardly leading temperature-dependent working safety valve (200) is in communication.

2. Occupant protection device according to claim 1,

characterized in that \

- The safety valve comprises a hole (210) in a wall (250) of a feed element (60) and a closure element (220) which is inserted from the outside into the hole, and

the closure element has at least two snap-action elements (230, 240), which snap against the wall and bear against the inside (280) of the wall.

3. occupant protection device according to claim 2,

characterized in that

- The closure element has a recess into which a locking element (350) is inserted from the outside, wherein the inserted locking element pushes the at least two snap elements to the outside, so that the

Snap elements are pressed against the hole wall (330) of the hole side.

4. occupant protection device according to claim 3,

characterized in that

- The recess formed in the closure element by a through hole (360) which is closed by the locking element.

5. occupant protection device according to claim 1,

characterized,

in that a closure element of the safety valve is formed by a pin (400) comprising a pin head (410) which is inserted from the inside into a hole in a wall of a feed element such that the pin head rests against the inside of the wall and

- The pin end (420) projecting through the hole to the outside to form a closure portion which is larger in cross section than the cross section of the hole, plastically deformed.

6. occupant protection device according to claim 1,

characterized in that

a closure element of the safety valve is formed by a blind rivet (500) which is inserted from the outside into a hole in a wall of a feed element and riveted to the wall.

7. occupant protection device according to claim 1,

characterized in that

a closure element of the safety valve is formed by a film (600) which is placed on a hole in a wall of a feed element from the outside or from the inside and closes the hole.

8. occupant protection device according to one of the preceding claims,

characterized in that

- The occupant protection device by a belt retractor (10) with a tensioner (30) is formed, the gas generator (40), one with a belt spindle (20) of the Belt retractor associated drive device and a feed element, in particular in the form of a feed pipe (60), which connects the gas generator and the drive device,

- In which the feed element a plurality of thrust bodies (70) are present, which are accelerated after triggering of the gas generator and drive the drive device for winding the seat belt directly or indirectly, and

- wherein the safety valve comprises a hole (210) in the feed element and the hole in the portion between the gas generator (40) and the first thrust body (70a) is arranged.

9. occupant protection device according to one of the preceding claims,

characterized in that

the safety valve comprises a closure element which closes the safety valve gas-tight as long as the material temperature of the closure element falls below a material limit temperature and

wherein the closure capability of the material of the closure element is reduced when the material limit temperature is exceeded and the safety valve is released, at the latest when gas is applied by the gas generator,

- The material limit temperature is less than the autoignition temperature of the gas generator and greater than the maximum temperature of the operating temperature range of the gas generator.

10. A method of manufacturing an occupant protection device with a pyrotechnic gas generator, characterized in that

- An outwardly leading hole is closed in a feed element with a temperature-dependent closure element.